Palaeoenvironmental implications from Lower Volga loess - Joint magnetic fabric and multi-proxy analyses

QUATERNARY SCIENCE REVIEWS

卷:267

Article

Koltringer, Chiara¹  Bradak, Balazs²  Stevens, Thomas¹  Almqvist, Bjarne¹  Banak, Adriano³  Lindner, Martin⁴  Kurbanov, Redzhep^5,6  Snowball, Ian¹ 

[1] Uppsala Univ, Dept Earth Sci, Villavagen 16, S-75236 Uppsala, Sweden

[2] Kobe Univ, Grad Sch Maritime Sci, Higashinada Ku, 5-1-1 Fukaeminami Machi, Kobe, Hyogo 6580022, Japan

[3] Croatian Geol Survey, Dept Geol, Sachsova 2, Zagreb, Croatia

[4] Univ Salzburg, Dept Chem & Phys Mat, Jakob Haringer Str 2a, A-5020 Salzburg, Austria

[5] Lomonosov Moscow State Univ, Fac Geog, MSU, MV Leninskie Gori 1, Moscow 119992, Russia

[6] RAS, Lab Evolutionary Geog, Inst Geog, Staromonetny 29, Moscow 119017, Russia

关键词: Anisotropy of magnetic susceptibility;    Scanning electron microscopy;    Loess;    Northern Caspian Sea region;    Palaeowinds;    Post-depositional reworking;    Chemical alteration;    Palaeoclimate reconstruction;   

DOI  :  10.1016/j.quascirev.2021.107057

来源: Elsevier

【 摘 要 】

Magnetic fabric (MF) investigations complemented by geochemical and grain surface analyses of the understudied and controversial marine isotope stage (MIS) 5 b, 4 and 3 loess deposits in the Lower Volga region, Russia show that the material has been transported and deposited by wind and to a large extent experienced post-depositional reworking. Grain surface features suggest that the material was glacially ground and fluvially transported prior to final aeolian deposition as loess. Secondary magnetic fabrics in the loess reveal pedogenic and cryogenic processes and a generally cold environment with brief shifts to warmer climate during late MIS 5 and MIS 3. Palaeowind reconstructions derived from preserved primary aeolian MF, indicate locally influenced westerly and north-westerly flow as part of a wider scale westerly wind pattern, similar to modern day winter conditions. We suggest that the climate of the last glacial in the Northern Caspian Lowland was cold and dry, with higher windspeeds and less variability during MIS 4 compared to MIS 3. (C) 2021 The Authors. Published by Elsevier Ltd.

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